1. Field of the Invention
The present invention relates to an electrical module assembly with an explosion-proof switch and, in particular to an electrical module assembly with a motor switch for an electrical power tool.
2. Description of the Prior Art
Contemporary power tools such as, e.g., chisel hammers, include an electrical module assembly with power electronics which is arranged in a compression-proof housing with minimal gap lengths for spark-quenching, whereby the power electronics is protected from explosion. In addition, contemporary electrical power tools require the use of explosion-proof motor switches which reliably prevent formation of sparks.
Conventionally, a contactless switch includes movable switching means, e.g., permanent magnets, which is actuated by associated actuation means, and sensory electronics for detecting the relative movement of the switching means. The sensory electronics may include a Hall-sensor that controls power electronics arranged in the current circuit of the electric motor of a power tool, whereby generation of switching sparks in prevented. For the necessary electrical connection of the sensory electronics with the inner power electronics, the actuation means, which is actuated from outside and extends through an opening formed in the wall of the module housing, also should be protected from explosion. To this end, the housing opening has minimal gap lengths and maximal gap widths for quenching the sparks.
German Publication DE-195 14 708 discloses a contactless Hall-push-button switch having respective separation walls between two displaceable slides with respective permanent magnets and two associated therewith, respectively, Hall-sensors. The separation wall is formed as a hat-shaped, turned from inside out, pocket. The turned, from inside out, pocket simultaneously serves as a support for a displaceable push-slide.
German Publication DE-32 20 914 discloses an explosion-proof, contactless Hall-rotary switch having a circular bottom elevation in which an operating shaft with two diametrically opposite permanent magnets is guided, and in which the magnetic field, which passes a separation wall, acts on a Hall-element that is located in a circular chamber separated from the separation wall. The separation wall forms a component of the integral structure of the switch which is arranged on the outside of the electrical module and requires that an opening be formed in the module housing for an electrical connection with the inner power electronics.
An object of the present invention is to provide an electrical module assembly with an explosion-proof switch and the module housing of which does not have any opening.